From The Wirecutter: The best cable modem (for most folks)

This post was done in partnership with The Wirecutter, a list of the best technology to buy. Read the full article below at TheWirecutter.com.

After researching 57 different cable modems, the $90 ARRIS / Motorola SurfBoard SB6141 DOCSIS 3.0 remains the cable modem we recommend for most people. If instead of renting from your ISP, you buy your own cable modem, you can get a better device and recoup the cost in as little as a year—and then start saving anywhere from $6-$10 each month, depending on your ISP's rental fees. Yes, you can probably find a slightly cheaper cable modem that only works with your ISP. We prefer our pick because its flexibility makes it a better long-term investment if you change service during the lifetime of the device. Unlike the competition, the SurfBoard is compatible with almost all of the fastest Internet plans from seven of the eight biggest cable Internet providers, including Charter, Comcast, and Time Warner Cable. You can move almost wherever you want and be assured that this buy-once, use-for-awhile device will still work. And you get the flexibility to switch providers if there's a better deal in your area.

How we picked

A great cable modem should support at least eight downstream channels and four upstream (8x4), which gives you plenty of overhead if you want to upgrade to faster service now (or if your ISP gives you faster service for free later). A 4x4 cable modem is too limiting, especially since you're probably going to hold on to your new cable modem for a few years. A 16x4 cable modem is way more than you need unless you're subscribing to your ISP's fastest plans (300 Mbps or greater)—you're more likely to see a speed boost going from 1x1 or 4x4 to 8x4; much less so going from 8x4 to 16x4.

Cable One recommends that its customers use an 8x4 cable modem for "the best speed performance." Representatives from Time Warner Cable told us that most of their networks outside of their "Maxx" markets—New York, Los Angeles, and Austin—use 8 downstream channels and 4 upstream channels. An 8x4 cable modem is a perfect match.

You should get a new cable modem if yours doesn't support DOCSIS 3.0. Google the model number of yours if you're not sure. DOCSIS 2.0 is considered obsolete and only supports one downstream channel and one upstream channel, so DOCSIS 2.0 modems can't avoid network congestion and can't support download speeds above 43Mbps.

You should get our pick if you don't already own a cable modem, if your cable modem doesn't support DOCSIS 3.0, or if you want to go from renting to owning.

DOCSIS 3.1 is a new standard looming on the horizon, which will keep ISPs pushing for faster, more-robust networks—Comcast expects to have DOCSIS 3.1-based Gigabit Internet this year, and other ISPs are likely to follow throughout 2016. However, we don’t think you need to hold out, because you could be saving money instead by buying now (your ISP might not be ready with DOCSIS 3.1 by the time you recoup what you would spend on our pick). Even when DOCSIS 3.1 is available, DOCSIS 3.0 modems will still work, and you may not want to pay more for a faster Internet plan and a new cable modem.

We came up with our pick by going over the lists of compatible cable modems for the nation's three biggest ISPs—Comcast, Time Warner Cable and Charter—as well as Cox. We ranked the modems by how many of these ISPs they support. Only three on our list worked with three or more, and only the Surfboard, our main pick, worked with all four. These became our contenders, as well as all the top 20 best-selling modems on Amazon (to make sure we didn't leave anything out).

We didn't consider any modems that double as wireless routers, because they're a poor investment. These hybrids are usually slower and less reliable than the combination of a separate modem and router. And if a hybrid model breaks, you'll lose your home Wi-Fi network and your Internet service.

Our pick

The ARRIS / Motorola Surfboard SB6141 cable modem is the best choice for most people right now because it’s the only one that works with most of the fastest national plans on seven of the eight biggest US cable ISPs, as well as Cox. And on top of that, it also has many thousands of glowing Amazon reviews to back it up, and a history of reliability.

The SB6141 supports eight downstream channels and four upstream channels. After network overhead, that gives you a maximum bandwidth of 304 Mbps downstream and 108 Mbps upstream. That's a lot faster than most cable-Internet plans, but that's okay—our pick can still help you get closer to the speed you pay for by reducing the effects of network congestion. Its ability to use more channels on your ISP's network is like adding extra lanes to a freeway. Congestion from your neighbors in one channel won't affect the speeds of the others.

Depending on your service speed and your ISP's network congestion, you may not see any improvement in speed over your previous modem. But even if you don't see a benefit now, our pick gives you the flexibility to get faster service in the future, whether you pay for the upgrade or your ISP upgrades your service for free. And it frees you from monthly modem rental fees.

More visitors to Buy A Cable Modem bought our pick than any other cable modem during the months we spent researching this article. On Amazon, our pick had an average rating of 4.4 with 5,006 total reviews. Our pick was also the second-best-selling cable modem on Amazon at the time, only bested by Motorola's slightly cheaper 4x4 cable modem, the Surfboard SB6121. (Our pick's extra channels are worth the $20 price difference.)

Our pick also comes with a one-year warranty. That might sound short, but cable modems are reliable—so much so that you could even buy a refurbished or used version of the SB6141 to save money. If it works for the first week, chances are it will work for a long time.

Additional Options

If our pick is sold out, or you can't find it, the Netgear CM400-100NAS DOCSIS 3.0 cable modem is our runner-up choice that also supports eight downstream channels and four upstream channels, as well as the same high-speed plans on the nation's three biggest ISPs: Comcast, Time Warner Cable, and Charter. Unlike our main pick, the CM400 isn't compatible with four of the nation's eight biggest ISPs: Suddenlink, Mediacom, WideOpenWest, or Cable One. And our pick has better reviews from more people who bought it.

For those looking to upgrade, the ARRIS / Motorola Surfboard SB6183 is a 16x4 cable modem, so it supports twice the download speeds of the SB6141, but few Internet plans offer that much speed. You'll need it only if you subscribe to a plan like Time Warner's 300Mbps Ultimate tier, found in locations like Los Angeles, New York City, and Austin. The SB6141 is fast enough for almost everyone else, and it's quite a bit cheaper. By the time most people's cable service gets near the limits of the SB6141, next-generation cable modems will be out. It doesn't make sense to get the SB6183 now unless you know you need it.

In closing

DOCSIS 3.1 is on the horizon, but the ARRIS / Motorola SurfBoard SB6141 is still the best cable modem for most people right now. It works with just about every cable ISP and supports most of the fastest Internet plans they offer. Even though most people don't pay for triple-digit Internet speeds, our pick lets you avoid network congestion to get you closer to your plan's maximums without being overkill or overpriced. More importantly, the SB6141 has a history of reliability and great reviews from thousands of satisfied users.